A solar furnace is a device composed of a large curved mirror which harnesses solar rays to produce a high temperature beam of light. Possible applications includes melting steel, making hydrogen fuel, or even burning hot dog sausages to a crisp. The furnace you’ll see in the following video can reach 2,400 °C (4,352 °C), enough to melt steel, but according to Wikipedia, some solar furnaces can reach temperature up to 3,000 °C (5,430 °F). Video after the jump.